GT-Grid & SI-Grid

Advanced Processing Services

Offering The Most Advanced Processing Services In The Industry

The integrity of basic profile and gridded survey data is fundamental to all subsequent use. Our strength is our familiarity with the airborne measurement environment providing us with the knowledge and insight to improve the true integrity of the data and not simply focus on cosmetic change.

Like other companies we use 3rd party software. The packages provide a lot of useful tools; however, if functionality is missing or inadequate, we have developed our own software tools. These include control line levelling and our GT-Grid & SI-Grid gridding methods that are an improvement to the conventional packages.

We take professional pride in applying our knowledge and skills to extract the most technical value from survey data.

Experience

Survey Contractors

Geotech

Fugro Dighem

Fugro Geoterrex

Goldak

Terraquest

New-Sense

Tundra

MPX

Compilation Clients

Vale

RTZ

Kennecott

SouthernEra

DeBeers

Metallex

Ontario Geological Survey

Minnesota Geological Survey

Introducing GT-Grid

GT-Grid is a software method developed by Scott Hogg & Associates to make full and effective use of measured magnetic gradients in the gridding process. The total field magnetic grid produced is fully compatible with the measured gradients throughout the map. The ability of GT-Grid to map complex geology, including magnetic structure trending close to the flight line direction, is unparalleled.

The GT-Grid process is an excellent way to re-process previous magnetic gradient data to realize full potential resolution. And even better - GT-Grid provides unmatched resolution and quality when paired with SHA’s Heli-GT magnetic gradiometer system.

GT-Grid Example 1 - GDS 1245 - Dog Lake & East Nipigon Areas

GDS 1245 is a re-processed data set published by the Ontario Geological Survey. The survey was flown at an altitude of 70m, with 200m and 400m line spacing. The original fixed-wing survey had recorded magnetic gradient data that had not been used to its full potential. The illustrations below present the vertical derivative calculated from each total field map type.

Calculated Vertical Gradient from conventional grid built from total field alone.

Calculated Vertical Gradient from GT-Grid built from total field and gradients.

GT-Grid Example 2 - GDS 1040 - Kapuskasing Chapleau Area

GDS 1040 – Kapuskasing Chapleau Area is a re-processed data set published by the Ontario Geological Survey. The survey was flown at an altitude of 70m, with 200m and 400m line spacing. The original fixed-wing survey had recorded magnetic gradient data that had not been used. The illustrations below present the vertical derivative calculated from each total field map type.

Published OGS/GSC Version - Calculated Vertical Gradient

GT-GRID Version - Calculated Vertical Gradient

Introducing SI-Grid

SI-Grid is a software method developed by Scott Hogg & Associates to actively interact with the gridding process for the purpose of building very high definition, coherent grids, from profile data. Surveys whose line spacing was inadequate to correctly present the magnetic complexity by conventional methods are an ideal candidate for SI-Grid.

SI-Grid Example 1 - OGS Erlis Data 1997

A comparison is presented between a total magnetic field map produced by SI-GRID, and one produced by Paterson Grant and Watson Ltd. for the Ontario Geological Survey in 1997, using a minimum curvature in combination with a GSC trend enhanced gridding technique (Keating 1995).

OGS 1997 ERLIS total magnetic field grid.

SI-GRID of total magnetic field using the same magnetic profile data as input.

SI-Grid Example 2 - Minnesota Geological Survey 2017

The Geological Survey of Minnesota has a large archive of aeromagnetic data collected around 1980. In 2017 a sample was re-processed and re-gridded using the SI-Grid technique.

Calculated Vertical Gradient of Original Survey

Calculated Vertical Gradient after Re-Compilation including SI-Grid

Our Most Popular Re-Processing Service

Our most popular re-processing service is cleaning and re-levelling aeromagnetic databases and re-gridding with our SI-Grid or GT-Grid process depending on gradient quality and availability. A variety of grid products can also be created. Vertical and horizontal derivatives, susceptibility maps, analytic signal and many other options are available.